Prediction of theaflavin and thearubigin content in black tea using a voltammetric electronic tongue

The two most important chemical groups that decide the liquor characteristics of black CTC (cut, torn and curled) tea are theaflavins (TF) and thearubigins (TR). Hence, a quick estimation of concentration of these compounds can significantly contribute to the evaluation process for the quality of finished tea in an objective manner. In this paper, a scheme for rapid measurement of concentration of TF and TR is described using a voltammetric electronic tongue with five working electrodes made of noble metals. The results indicate good correlation of electronic tongue predictions with the actual concentrations obtained using ultraviolet–visible spectrophotometer.

Research Highlights
► Theaflavins (TF) and Thearubigins (TR) determine the liquor characteristics of tea.
► Concentrations of TF and TR are measured using a voltammetric electronic tongue.
► Correlation models developed using PLSR, SVR and BP-MLP.
► The results indicate good correlation with UV-Vis spectrophotometer readings.